digital cookies and crumbs

http://www.digitalagenda.ca/node/119

http://sitestat.com/privacy/

http://www.futureplc.com/cookies-policy/how-can-i-manage-or-opt-out-of-cookies/

http://en.wikipedia.org/wiki/Breadcrumb_(navigation)

http://arstechnica.com/security/2014/07/mobile-apps-cookies-leave-a-data-trail-behind-you/